THE SCIENCE OF LIFE

THE SCIENCE OF LIFE Reference: Modern Biology CHAPTER 1

Certain ‘themes’ unify all Biological Sciences. Living things, no matter how diverse, share common characteristics. BIG IDEA

Cell Structure & Function Stability & Homeostasis Reproduction & Inheritance Evolution Interdependence of Organisms Section 1-1 unifying themes of biology Matter, Energy & Organization

Biology - The Study of Life BIOLOGY-the study of all living things. EXAMPLES of Biological Sciences: • Histology-the study cells and tissues • Genetics-the study of how traits are inherited • Microbiology-the study of microorganisms • Ecology-how organisms interact with each other and their environment.

Biology - The Study of Life ORGANISMS-living things • EXAMPLES: • Plants • Insects • Humans • Bacteria

Biology is unified by certain themes, or patterns that connect all living things: Cell Structure and Function Stability & Homeostasis Reproduction and Inheritance Evolution Interdependence of organisms Matter, Energy & Organization 6 Major Themes of Biology

All organisms are made of and develop from cells. UNICELLULAR-made of only one cell (amoeba, paramecium) MULTICELLULAR-made up of many different types of cells working together (tree, spider, dog) 1. Cell structure & function

Unicellular– Each new cell is identical to the parent. All developing organisms are exact clones of their parents. Multicellular– Cells become different from each other as they multiply. All developing organisms are a combination of two parents, but are different from them. 1. Cell structure & function DIFFERENTIATION

1. Cell structure & function Cell - One Name, Many Types All cells, no matter what kind, have similarities, as well as differences. Certain cell structures determine the function of the cell. Examples: Red Blood Cells – carry oxygen Plant cells – carry out photosynthesis Unicellular Microorganisms – carry out ALL of life processes.

All living things must maintain stable internal conditions to survive. Homeostasis- stable level of internal conditions found in all living cells. EXAMPLES: temperature water content food intake 2. Stability & homeostasis

All organisms come from existing organisms. They reproduce and transfer their hereditary information to their offspring. 2 Types of Reproduction: ASEXUAL REPRODUCTION-heredity information is not combined - only one organism’s DNA is used. Offspring are identical to parent. EXAMPLES: bacteria and other unicellular organisms SEXUAL REPRODUCTION- heredity information (DNA)from two organisms from the same species combine. Offspring are different from both parents and from any other offspring EXAMPLE: monkey having a baby Egg and sperm  zygote (fertilized egg). 3. Reproduction & Inheritance

Organisms transfer their hereditary information to their offspring in the form of deoxyribonucleic acid (DNA) – the “book” of life. A gene is a short segment of DNA that contains the instructions for a single trait. vs. 3. Reproduction & Inheritance

3. Reproduction & Inheritance

4. Evolution Populations of organisms evolve or change over time. Evolution -population of organism changes over generations (time).

4. Evolution

All living organisms interact with other living organisms and their non-living environment. 5. Interdependence of organisms

The branch of biology concerned with these interactions is called Ecology. Ecology-the study of how organisms interact with each other and with their environment. 5. Interdependence of organisms

All living organisms need a constant supply of energy. How organisms obtain, use and transfer energy is a major topic of study in biology. ALL energy for life on earth comes from the SUN. 6. matter, energy & organization

Autotrophs-organisms that can get energy by producing their own food. EXAMPLES: plants and some unicellular organisms Heteroptrophs-organisms that must get energy by eating other organisms EXAMPLES: some unicellular organisms, all animals and fungi 6. matter, energy & organization

Go to the following link and take the Concept Review Quiz 1_1 … https://sites.google.com/site/nhsbiologybunch/home/biology/1-unit-the-science-of-life/concept-review-1

The World of Biology

In your notebook, respond to the following: Suppose you discovered an unidentified object on your way home from school. How would you determine if it is a living or a nonliving thing? DO NOW:

The Characteristics of Life All organisms, no matter how different, have certain characteristics in common THE CHARACTERISTICS OF LIFE !

1. MADE OF CELLS All living things are composed of cells…

2. ORGANIZED All living things are highly organized… They are organized at molecular and cellular level. Cell structures (organelles) carry out specific functions.

2. ORGANIZED Cells  tissues Tissues  organs Organs  systems Systems ORGANISM

2. ORGANIZED

3. USE ENERGY All living things use energy… All organisms use energy to grow, reproduce and make repairs. Metabolism-all of the chemical processes that take place in a living organism.

4. HOMEOSTASIS All Living things maintain stable internal conditions and respond to their environment. Response - reaction to input (stimulus) from the world. May be simple or complex. EXAMPLE: Bird fluffing its feathers to stay warm

5. GROW & DEVELOP All living things grow and develop…

5. GROW & DEVELOP Growth is the increase in the amount of living material in an organism. The series of changes an organism undergoes in reaching its final adult form is called development.

6. REPRODUCTION All living things reproduce… Create more of their own species. Essential to the survival of the species…NOT of the reproducing organism.

Do Now Compare and Contrast: Make a chart that lists the six characteristics of life. Watch the following video clip, IS IT ALIVE…OR IS IT?? Use the chart to help you determine whether the object is living or non-living. Support your decision.

What is Science? Science is a process that produces a body of knowledge! Science is carried out because people : Wonder… Are Curious… Ask questions… That is the beginning of all scientific research. Science – Learning About the World

Science – Learning About the World The goal of science is to: investigate and understand the natural world. explain events in the natural world. use those explanations to make useful predictions. Gain knowledge: Knowledge from science can be used to improve life. Example: polio vaccine, penicillin, genetically enhanced food

Watch this Video How simple ideas lead to scientific discovery Respond to the video in your notebook.

BIOLOGY AS A SCIENCE

Methods of Science

The Scientific Method What methods do scientists use to learn about the natural world? Scientific Method: a guided approach, or series of steps to arrive at an answer to a question or problem through some type of investigation or experimentation.

The Scientific Method The Scientific Method has approximately 6 steps: • Observation • asking questions • Collecting data • Hypothesis (explains their observations and can be tested!!) • Experiment (testing your hypothesis) • Collecting, Organizing & Analyzing Data • Conclusion • Communication

Step 1 - Observation • Use the 5 senses to perceive objects or events. • Asking a question • Based on observations; one or more questions are generated.

Step 2 – Forming a Hypothesis Hypothesis-a possible explanation for what was observed and why it should come true . • it must be able to be tested • If/then statement-often written in this form. • Example:Ifgiving tomato plants “Tomato Grow” plant food increases the size of the tomatoes a plant produces, then tomato plants feed “Tomato Grow” may produce larger tomatoes

Step 3 - Experimenting Most experiments in Biology are controlled experiments • performed to test your hypothesis (confirm or disprove it) • Based on a comparison of a control group with an experimental group. • Used to gather data under controlled conditions. • Data-bits of information gathered during the experiment.

Step 3 - Experimenting All factors in the control group and the experimental groupare identical except for one: • independent variable • what is being tested During the experiment, observations and measurements are taken from both groups, looking specifically at another factor or variable: • dependent variable • dependent because it is driven by/or results from the independent variable.

Step 3 - Experimenting To have a controlled experiment, two groups must be tested: • Control Group- the group where all the variables remain constant – the "normal group” • Experimental Group- the group exposed to the experimental factor (independent variable – what is being tested), but is otherwise IDENTICAL to the control group.

Step 3 - Experimenting Variables: Independent Variable-the factor deliberately changed by the scientist; the one factor that is different between the groups. In a controlled experiment, only the independent variable changes. **Independent variable causes a change in what you are measuring – the dependent variable** Dependent Variable-the one thing that is measured in the experiment, directly influenced by the independent variable.

THE SCIENCE OF LIFE